Publication Date

12-2024

Date of Final Oral Examination (Defense)

10-17-2024

Type of Culminating Activity

Thesis

Degree Title

Master of Science in Civil Engineering

Department

Civil Engineering

Supervisory Committee Chair

Bhaskar Chittoori, Ph.D., P.E.

Supervisory Committee Co-Chair

Nick Hudyma, Ph.D., P.E.

Supervisory Committee Member

Yang Lu, Ph.D., P.E.

Abstract

The research, development, and implementation of sustainable and resilient infrastructure is a critical mission for all aspects of modern Civil Engineering. The engineering and construction sector accounts for 37% of all global greenhouse gas emissions, comprising the largest proportion of any industry (Kafu-Quvane et al. 2024). Typically comprising 100% of base and subbase layers, 90% of asphalt pavement, and 80% of concrete pavement, it takes approximately 38,000 tons of aggregate to construct a single-lane mile of interstate highway (Feuling 2024). This presents significant environmental challenges due to the negative impacts of quarrying and aggregate transportation such as habitat destruction, biodiversity loss, ecosystem disruption, resource depletion, and air, water, and noise pollution. Developing innovative methods to produce equally strong, durable, and economical roadways while decreasing our environmental footprint is essential. One solution is the utilization and alteration of native soil through Microbial-Induced Calcite Precipitation (MICP).

Previous research in Boise State's Sustainable and Resilient Geotechnical Engineering (SuRGE) Laboratory, has shown MICP to be a viable and economical stabilization option in soils with a fines content of up to 30% in small-scale laboratory testing (Pisati 2023), and large-scale field testing (Dahal 2024). However, the timeline to sufficiently alter the properties of the soil matrix for construction is currently too long to be chosen by a contractor or design engineer. This treatment time must be reduced significantly to make MICP a competitive construction technique for wide-scale adoption.

The primary objective of this research is to decrease MICP treatment time by combining MICP and calcium-based stabilizers (CBSs) such as hydrated lime, cement, and fly ash. The main methods used to evaluate specimen performance were Unconfined Compressive Strength (UCS), Calcium Carbonate Content (CCC), and Free Swell Index (FSI). This study targets the discrepancy between samples with a single preliminary round (Biostimulation and Biocementation) of MICP treatment, those with multiple rounds, and those left untreated before the introduction of a CBS.

Comments

https://orcid.org/0009-0009-4250-8973

DOI

10.18122/td.2286.boisestate

Download

Share

COinS